1. Field of the Invention
The present invention relates to a sheet supplying apparatus that includes a sheet holder in which a plurality of recording sheets are stacked on each other; a sheet feeding device; and a sheet-separate body, and that supplies, to a recording device, the recording sheets, one by one, while separating the sheets from each other.
2. Discussion of Related Art
There is known an image recording apparatus, such as a printer, a copier, or a facsimile machine, that includes a sheet supplying device for supplying, to an image recording portion of the apparatus, a plurality of cut sheets each as a recording medium, one by one, while separating each one of the cut sheets from the remaining cut sheets.
For example, Patent Document 1 (i.e., Japanese Patent Application Publication No. 2002-173240) discloses a sheet supplying device including an upwardly open, sheet cassette that accommodates a plurality of cut sheets in a substantially horizontally stacked state; a plurality of inclined sheet-separate plates that are provided at a downstream end of the sheet cassette as seen in a sheet-feed direction in which each cut sheet is fed, such that the inclined sheet-separate plates are distant from each other by respective appropriate distances in a widthwise direction of each cut sheet; a sheet-feed roller that is provided above the sheet cassette, is pressed against the uppermost one of the stacked cut sheets, and is driven or rotated to feed the uppermost cut sheet; and a U-turn path (i.e., a U-shaped sheet guide) that cooperates with the sheet-feed roller and the inclined sheet-separate plates to separate the uppermost cut sheet from the remaining cut sheets and feed the separated cut sheet to an image recording portion provided above the sheet cassette.
In addition, Patent Document 2 (i.e., Japanese Patent Application Publication No. 2004-149297 or its corresponding U.S. Patent Application Publication No. 2004-084831) discloses a sheet supplying device including an inclined wall on which a plurality of cut sheets are placed in a stacked state such that the cut sheets are inclined obliquely downward; a bottom plate that is provided below the inclined wall, has an obtuse angle with respect to an upper surface of the inclined wall, and extends in a widthwise direction of each cut sheet; and a sheet-feed roller that is pressed against the uppermost one of the cut sheets stacked on the inclined wall and feeds the uppermost cut sheet. The bottom plate is provided with a sheet-separate portion formed of a stainless steel. The sheet-separate portion includes a plurality of projecting portions that are arranged, in a sheet-feed direction in which each cut sheet is fed, such that the projecting portions are distant from each other by a regular interval of distance; a plurality of arm portions each of which supports a corresponding one of the projecting portions, on either side of the one projecting portion; and a continuous base portion that continuously connects the arm portions to each other and thereby supports the arm portions. The sheet-separate portion is held by a holder that is formed of a metallic sheet and is fixed to the bottom plate, such that the projecting portions project by a predetermined amount through an elongate hole of the holder that is elongate in the sheet-feed direction. When the sheet-feed roller, pressed against the uppermost one of the stacked cut sheets, is driven or rotated to feed the uppermost cut sheet, a lower end of the uppermost cut sheet presses each one of the projecting portions, and consequently the each projecting portion is moved downward into the elongate hole of the holder because of elastic deformation of the corresponding arm portion. Since, however, the remaining cut sheets are not moved because respective lower ends thereof are engaged with the other projecting portions that remain projecting from the elongate hole, only the uppermost cut sheet can be separated from the other cut sheets and fed forward.
Generally, in an image recording apparatus, a recording portion is provided in a space above a sheet tray or cassette, for the purpose of reducing a footprint of the apparatus, and the recording portion and the sheet cassette are connected to each other by a sheet reversing and conveying guide (i.e., a U-turn sheet guide) that is constituted by a pair of guide members. This image recording apparatus is disclosed by, e.g., Patent Document 1.
The sheet reversing and conveying guide has, in a sheet-reverse portion thereof where a direction of movement of each cut sheet is reversed, two sheet-convey rollers that cooperate with each other to nip a leading end portion of the uppermost cut sheet that has been fed forward by the sheet-feed roller and has been separated by the inclined sheet-separate plates. However, when the sheet-convey rollers starts nipping the leading end portion of the uppermost cut sheet, no drive force is transmitted to the sheet-feed roller any more, so that the sheet-feed roller is freely rotated. On the other hand, the sheet-convey rollers starts applying a conveying force to the cut sheet, so that the leading end portion of the cut sheet is forced to contact two register rollers provided in front of the recording portion, i.e., on an upstream side of the recording portion as seen in the sheet-convey direction. Therefore, even if the position of the cut sheet may be deviated from a correct position, the deviation can be corrected, i.e., registered.
After the sheet-convey rollers start nipping the leading end portion of the cut sheet, the cut sheet that has been forcedly fed forward while contacting the inclined sheet-separate plates and an outer one of the two guide members, then contacts the outer guide member because of only a shape restoring force of the cut sheet itself. Therefore, a recording surface of the cut sheet can be prevented from being damaged.
However, in the case where a power transmission device that transmits power to the sheet-convey rollers is omitted, or in the case where the sheet-convey rollers are omitted for the purpose of reducing a production cost of the sheet supplying apparatus, the sheet-feed roller needs to feed and convey the cut sheet till the leading end of the cut sheet is nipped by the register rollers. In each case, therefore, the recording surface of the cut sheet is forcedly engaged with the outer guide member, so that the recording surface may be easily damaged.
In particular, in the case where the cut sheet is a glossy sheet that is suitable for recording of a photographic image and exhibits a strong shape-restoring force, the cut sheet receives a great resisting force from the outer guide member, so that a recording surface of the cut sheet may be easily damaged. In addition, if a radius of curvature of the sheet reversing and conveying guide is small, this tendency is increased. Moreover, in the case where projecting portions as sheet-separate portions that are formed of metallic sheet are so disposed as to project from an inclined sheet-separate plate, for the purpose of reliable separation of each cut sheet from the remaining cut sheets, a deep scar may occur to the recording surface of the glossy sheet.